collective
these little mammals these are the
boundaries as they come to be
mentioned these lemmings are those of
small rodents which it may be
heard in association with
mass movements or so the
video game enthusiasts know them
like let’s say a video game that simulates
certain behaviors associated with these
lemmings for us biologist
of course we had our doubts about
the reality of a collective suicide at
animals especially en masse
how does the caricaturist interpret it
gary larson you see lemmings that
rush to the sea all go
to die with an exception the one that is going
perpetuate the species it is the one who
will be equipped with lifebuoy
short for us so we searched
in vain also in the literature of
documents presenting his
but we can look for a long time
we do not find anyway that we
motivated to put in place at a
long-term project that will allow
accompany you so you my companion
would have tonight at the option of moors where
we are we go every summer
for 30 years to study these lemmings
it is the mines whose territory
essentially comprises the zones
hostile that circles the Arctic Ocean
you have here Scandinavia the Siberia
you find in alaska
in their Canadian and in grenland bones they
are confined in the northeastern part
and here you see our study site
therefore more than a thousand kilometers
north of iceland
lemming habitat in summer
a bit reminiscent of the summit zone of
ipod over 2000 meters so
it’s very empowering habitats
stunned here a mid shot
July noted the ongoing presence of
singing other snow melting and above
very rare vegetation but it’s
its lemming habitat during the
course was Arctic summer article
it lasts an average of two to three months
but for lemming its habitat
principal it’s actually frees the
particularity of lemmings is
live for nine months under the mantle
snowy
that’s where they breed and
it’s really paradoxical to know that
under such extreme conditions with
winter temperatures up to -40 the
lemming remains active unlike
water marmots who here will hibernate
but the mines remain active under the
snow is so this environment the
lemming sharing with others
cash
we will see which of the herbivores
tank the lemming it’s an herbivore it’s
a rodent he is a bit related
with our lobby campaigns and in these
backgrounds so here we see it consuming
some ground kittens
but they share this habitat with
also musk oxen and hare
Arctic
incidentally also with ptarmigan
seniors so we have a community
of herbivores but in these environments
when we talk about herbivores ya
maybe also predators who
feed on it let’s see which
so the predators who
fond of delémont it is in particular
the discounts that you also have you
find here in the hard huh you have
the polar fox incidentally too
the white wolf and especially the owl
dainese so the snow owl and
the ermine are very predatory
specialized in lemming
the absence of lemmings you have neither
ermine you have no owl
snow and so it’s a little these
interactions that are studied on the spot
you have here the food chain
you see all who are
dependent on lemmings and this is in
studying these interactions
so we thought we might have a
chance to elucidate these cycles of
lemmings conduct research in the middle
Arctic is first of all a great challenge
logistics
we work in one of the most
remote world
it is the largest national park the
Northeast Greenland National Park y
does one and a half times the surface the
France there are fewer people than in
a row tonight here so the father
just the staff of the bases and so
access necessarily there are no two
airlines that serve so it
must arrange everything yourself
a big logistical challenge to
access and also to carry out the
searches in the summer especially lack of
comfort we arrive on site in the month of
June is still light and cast
intervenes during snowmelt
usually towards the end of the month of
June which then clears the tundra and
that’s when we put in
place we followed and it’s followed consists
basically in a method
indirect ie we want to know
how evolution evolves
lemming population from one year to
the other so of course we’re capturing
was that we also team small
mini tags but there the close
the main thing is that we will count their
various nests
they live in winter under the snow and
that’s where they breed themselves
can reproduce until there is
up to 5 doors and in the space of a
in the winter you report the
reproductive potential and that’s
especially the nests here on the right that are
interesting for us since we
reveals that n ‘there were
presented by the ermine hermine
it’s the only predator likely to
hunt them in winter under the snow and
the ermine then as soon as she spots in
ideas will get me the hairs of
these three to make his own bag
sleeping and this is for us a
indication of the presence of ermine in
winter so it’s often a job
very tedious to document the
presence of all is neither diverse nor
count up to 4000 years tic
so actually it swarms all
four years or five years and then after we
almost sees more we go down to less
of 50 nor various and so we also try
to model the interactions so we
will know how many lemmings are
consumed by each predator by
example snow owls can
to consume up to twenty by
day and you see the impact that this
can have on a population but also
the foxes the abbot the ermines
intervene and so we could model
all these interactions and that we have
published elsewhere and that shows well
that it’s the relationship with the ermine that
is fundamental in the determinism of
these cycles ie every 4-5
years so we have a peak of lemmings and the
Ermine practically achieves with a
year of delay since we imagine
lemmings can have five litters
by winter so from scratch to
almost 100 while the east
but the east she is disabled but
as soon as they can
reproduce
she will help to collapse
lemming numbers to one aspect
so we continue this monitoring so
this is the long-term study
done now thirty years we have
observations and what strikes it’s
actually the absence the 15
first years we had pretty
fluctuations that fades from
glass around 2011 initially had not
explanation still very convincing but
obviously the changes of
the snow that we also know here
in the alps can be incriminated
in this phenomenon
it remains so we also know that
the Arctic is at the forefront of
climate change which is a lot
more intense than in our regions
temperate
so precisely concerning the effects
climate change is another
aspect where we realize it in
our daily life that really the
conditions change
it is by observing this statistic
we recorded all the meetings
with bears berne since our
camp is right on the coast and
it’s not uncommon to see the bears
whites that lands on the mainland
in statistics you see in blue
it’s the bears still on the ice in
brens and bears who are on the beach
and towards the bears far inside
land we do not expect at all to
meet
and precisely you see that also towards
the year 2000 2002 practically the day
next day we had bears
regularly while previously
look never posed problem is that
it’s there to document a little the
daily so one where that they
check our weather station
perhaps they rely offense
if climate change is good
indicated many times
nato have been lacerated so this is
really also a challenge at the level of
security
and you see our trappers and
the bear that disemboweled him to very
many times
so we are very, very often exposed
to bear visits
so go on we have to take action
accordingly and really it makes
now part of our everyday life and
precisely so for the bears so it’s
a challenge to know if they will be able to
survive since they are now
ice pack during a longer
long period and which they come on
land is therefore for us too
it’s a challenge is actually so for
conclude can tell if the lemmings in
done there is no this one but in
anyway the reality the arctic and
20 years of change
very clear climate
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